What is DNS server and how does it work?

A DNS server is basically a phone book or a record of the Internet. In what is DNS server and how does it work? we will try to answer this question. to make it more understandable.

What is dns server and how it works
What is DNS server and how it works | Image by Gerd Altmann from Pixabay

What is domain name server (DNS)?

All the internet users that access websites or connecting to websites, using different devices through IP addresses. Web browsers, such as the Internet Explorer, Chrome or Mozilla Firefox interact through the device’s IP addresses. The main purpose of the DNS server is to translate and convert the domain name into the site’s IP address so that browsers can load the sites on the devices.

The DNS server makes it easy for humans to access information using the Internet browser. Each device connected to the Global Internet has a distinctive IP address. These IP addresses are like the devices’ identities. The devices use the IP addresses to get connected with the other devices.

DNS records easy for humans:

DNS servers keep a record of all the IP addresses of the devices. The DNS server takes the DNS records of the domain names and converts it into the unique IP addresses.

These DNS records make it easy for humans to access information as they won’t have to memorize the IP address for each device or web site.

IP addresses and alphanumeric variable codes are difficult to be memorized by the humans. DNS records make it easy for them to connect to the other devices.

The DNS records are managed, maintained, processed and accessed only by the DNS servers. Its prime purpose is to make the websites on the Internet accessible to the public. The DNS server is typically built on hardware, but the hardware runs a specific DNS software. DNS servers are always connected to the Internet.

When are the DNS servers used?

If you type a URL into a search engine or on a web browser, such as the Google, the DNS resolver scans through the net, to detect the IP address that converts to a certain domain name. The DNS resolver checks through the DNS records of a DNS server, one by one, to detect the specified domain name.

If the information associated with the IP address is found, the DNS resolver filters the images, texts, documents and videos and displays it in front of you as a whole website or a web page.

What are CNAME records?

CNAME records in DNS servers or DNS records are used to point one domain name into another one. For instance, when you access example.com and www.example.com, they are not different websites. They are hosted by a single server and are the same. But, the DNS server may file them separately in the DNS records.

The CNAME records allow you to maintain a single record instead of two different records. For instance, if DNS record A points out to the site: example.com, the CNAME record indicates the site: www.example.com to the record A.

Consequently, the example.com indicates to the same IP address as well as the www.example.com, through CNAME records.

In short, it is one of the Domain Name’s resources and it helps us to run various services from the same IP address.

CNAME records vs A records?

Ever ask yourself what is the diff between A record and CNAME record? well, CNAME can map a domain name to point another domain name and A record map domain name into an IP address.


CNAME map name to name – example.com -> www.example.com.

A record map name to number (IP) – example.com ->

How does a DNS server work?

Matching the domain name:

It is hard for humans to remember IP addresses. Instead, we can remember the site address, such as www.example.com. When we search for a particular URL on the browser, your browser forwards a request to the internet to find a similar or the exact site for www.example.com. The request is to find the domain name associated with the IP address for a match.

Recursive DNS resolver actually requests the browser to search for the associated domain name. The recursive DNS resolver is most likely to be operated by your Internet Service Provider. The recursive DNS resolver detects the authentic DNS servers, to request for a query.

Operation of the root server:

The first DNS server to receive the recursive DNS resolver’s request would be the root server. The root server is an all-in-one server to contain DNS-based information or the DNS records, about the high-level domains.

The perfect example of a high-level domain is .com. To fulfill your request, the recursive DNS resolver asks about all the DNS-based information from the root server. The root servers are operational across the world and contain all the DNS-based information.

Sending the query to the nearest root server:

There are millions of root servers distributed all around the world. They are spread strategically across the world, to maintain the internet activity ratio. The DNS sends your request to the nearest root server possible.

Verisign root servers are responsible for developing an evenly distributed internet infrastructure. The VeriSign root servers are typically used to enhance the speed and performance of the internet, across the world.

Operation of the top-level domain server:

The operation of the top-level domain server is to have DNS records for the second-level domains, associated with the high-level domains. When your request reaches the top-level domain server, it will instantly provide with the IP address associated with the server of the domain’s name.

The domain’s name server:

The domain’s name server accepts the query by the recursive DNS resolver. The DNS server scans through the DNS records and matches the IP address for the full domain name server. The answer is then transferred back to the DNS recursive resolver.

The appearance of the website:

Now, that the DNS recursive resolver knows the IP address, it tells the browser about the IP address according to the request. The browser then forwards the request to the website, to make it appear on your screen.

What is a DNS port?

All the DNS servers accept the requests on DNS port 53. All the DNS queries are forwarded to port 53, also known as the DNS port. Port 53 is the default port that DNS server use.

Final words:

The purpose of the DNS server is to provide convenience to humans. It is impossible for humans to remember all the IP addresses. Humans only need to remember the hostname, in order to access information on the internet.

Here is a little test you can do:

Open your web browser copy and paste this into your browser:

What do you see?

Now, think about that, if there was no DNS all the sites should be accessed by IP address…

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